Heating furnace



-Dec. 1924. 1,518,323

w. H. HAZARD HEAT I NG FURNACE Filed Aug. 22, 1921 2 Sheets-Sheet 1 4 il 24 a; .50 Y

I r V V v i v a I l Patented 9, 1924.

UNITED STATES PATENT OFFICE.

WILLIAM H. HAZARD, F JANESVILLE, WISCONSIN, ASSIGNOR T0 GENERAL MOTORSCORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OF DELAWARE.

HEATING FURNACE.-

Application filed August 22, 1921. Serial No. 494,269.

To all whom it may concern:

Be it known that 1, WILLIAM H. HAZARD, a citizen of the United'States ofAmerica, and a resident of the city of J anesville, county of Rock, andState of Wisconsin,

have invented certain new and useful Improvements in Heating Furnaces,of which the following is a full, clear, concise, and exact description,such as will enable others skilled in the art to which the inventionrelates to make and use the same, reference I being made therein to theaccompanying,

drawings, which form a part of this specification.

My invention relates to high temperature furnaces, and particularly tosuch as are used to heat articles that are to be forged and to which apart has to be welded, such as plowshares which commonly have a sep- 2arate point welded to the main body of the share.

The principal object of my invention is to provide an improved furnaceconsisting of two heating" chambers, one. in which the article is heatedall over to a temperature suitable for forging, and in the other ofwhich the heat is concentrated on a small ortion to which another pieceof metal is to be welded.

A further object of my invention is to pro .vide an improved furnacehaving a means for continuously moving the articles or devices that areto be heated from an opening in one end wall of the furnace to anopening in the other end wall.

A further object of my invention is to provide an improved furnacewherein the heating chambers are so arranged that the article that is tobe heated, upon entering the furnace, encounters only a moderatetemperature and is gradually moved along by a conveying means into aregion of higher temperature; so that when it reaches the end of thefurnace it has reached its maximum temperature. This prevents the metalof the article heated from being crystallized or otherwise injured, asit would be if it were heated too quickly.

A further object of my invention is to provide an improved furnaceconsisting of two ch mbers, one of which has a considerably highertemperature than the other;-

and wherein the surplus heat of the hotter chamber is used to partiallybring the temperature of the other up to a given degree.

A further object of my invention is to provide an improved furnaceconsisting of two chambers, one of which is heated to a highertemperature than the other; and wherein the two chambers are constructedin such a way that the one which generates the higher temperature may beremoved and another built in its place without disturb-v ing the chamberwhich generates the lower temperature; as it is obvious that the chamherhaving the higher temperature will burn out much sooner than the other.

With the above and other objects in view, my invention consists of animproved high temperature furnace and subsidiary parts and auxiliaryfeatures thereof illustrated in the accompanying drawings andhereinafter described and claimed; and in such variations andmodifications thereof, within the scope of the concluding claims, aswillbe obvious to those skilled in the art to which my inventionrelates.

Referring now to the drawings wherein the preferred embodiment of myinvention is illustrated Figure 1 is a sectional plan View of myimproved furnace, taken upon the line 11 of Figure 2. p

Figure 2 is a sectional side view and is taken upon the line 2-2 ofFigure 1.

Figure 3 is a sectional view taken upon the line 3-3 of. Figure 1.

Figure 4 is an end elevation as seen from a pi osition to the right ofFigure 1.

igure 5 is a sectional view taken upon the line 55 of Figure 1.

In the drawings, the reference numeral 10 designates a heating chamber18 in which articles to be heated such as plowshares 11 are brought to afor ing heat, while 12 is another heating cham r in which the points 13of the shares 11 are brought to a welding heat. The chamber 10 is formedby fire brick walls 14, a roof 15 and floor 16; while the chamber 12 isformed by walls 17, a roof 18 and floor 19. Throughthe wall 14 and intothe chamber 10 runs a gas burner 20 from which comes the flame whichsupplies the forgin heat; and through the walls 17 and into t e chamber12 runs a gas burner 32 from which comes the flame whichosupplies thewelding heat.

Through the chamber 10 runs a conveyor comprising two conveyor chainswhich are made up of links 21 held in roper relation to each otherbyrbraces 22. 11 each link 21. is a lug 23 upon which the plowshares 11rest. The conveyor chains are driven by the two sprockets 24 through theshaft 25 and run around the two idler sprockets 26, mounted on the shaft27. In the furnace the links 21 run upon pipes 28, through which coldwater is pumped, which keeps the pipes 28 from being burnt out by theextreme heat and keeps the conveyor chain from becoming too hot.

In the walls 14 and 17 are openings 29 in the form of long narrow slotsalongside which the conveyor runs and through which the points 13 of theshares 11 pass. The shares are placed upon the conveyor chain at theleft-hand end of the. furnace and pass thereinto through an opening 30,and are moved very slowly toward the right. When they first enter thechamber 10 the heat is not very intense, but as they move to the rightthe temperature increases. By the time they approach the chamber 12 thewhole share has been brought to a forging heat. Therefore when the point13 enters the chamber 12 it is not subjected to a severe change intemperature, as it is already very hot and the difference between theforging and welding heats is not enough to affect the composition of themetal.

At the right-hand end of the furnace is an opening 31 through which theoperator of a dro hammer removes the red-hot shares. If; then performsthe forging and welding operations and returns to the furnace, foranother plowshare. In case the operator should fail to remove one of theshares through the opening 31, it will pass through the o nin 33 in theright-hand walls 14 and 1 of tie heating chamber 10, 1.2 and cause abalanced fireproof trap door 34 to swing outwardly, and run off the endof the conveyor chain and drop to the floor. The door 34 serves toretain the heat within the chambers 10 and 12; and the lugs 23 on thelinks 21 of the conveyor chains are provided to keep the shares up offthe chains, so that the heat will be allowed to circulate under theshares as much as possible.

The roof 15 of the chamber 10 curves downward toward the conveyor chainside of the furnace, and the frame shoots from g the burner 20diagonally across the cham ber and is deflected downwardly by the roofand around the shares 11, heating them gradually to a forging heat. Inthe chamber 12 the flame shoots from the burner 32 ed opening;

directly on the under side of the points 13 of the shares 11, heatingthem to a whitehot heat for welding.

It will be seen that as there is considerable pressure within thechamber 12, quite an amount of the heat therein will be forced outthrough the openings 29 into the chamber 10, thus helping to heat thislast-mentioned chamber.

Operated by the heat within the chamber 12 is a thermostatic regulator35 which con trols the burner 32, thus keeping the temperature in thechamber at the proper degree for welding; as it is very necessary thatthe welding temperature should stay the same, while the forgingtemperature in the chamber 10 may vary considerably without affectingthe operation of the furnace as a whole. The chambers 10 and 12 areshown quite short in order that the views illustrating the inventionwill not be inordinately long. They may as a matter of course be made ofany length, and ordinarily their length will be such that more thanthree plow shares at a time will be in the chamber 10, and more than twoat a time will be having their points heated in the chamber 12, in orderthat both the forging and the welding heatswill be imparted to thesharesgradually as they move through the furnace.

Having thus described and explained my invention I claim and desire tosecure by Letters Patent:

1. In a furnace of the class described, a heatingchamber and means forheatin the same; a second heating chamber partitioned off from but whichsecond chamber is in permanently open communication with saidfirst-mentioned chamber through a restrictmeans for heating said secondchamber to a temperature higher than that of said first mentionedchamber; andmeans for moving articles to be heated through the furnace.

2. In a furnace of the class described, a heating chamber and means forheating the same; a second heating chamber in ermanently opencommunication with sai firstmentioned chamber through a slot extendingalong the same; means for heating said second chamber; and a conveyoradapted to move articles to be heated through the furnace and whichconveyor extends alongside the slot aforesaid.

I11 a furnace of the class described, a heating chamber and means forheating the same; a second heating chamber in rmanently opencommunication with said first mentioned chamber through a slot extendingthroughout the length of said second chamber; means for heating saidsecond chamber to a temperature higher than that of said first-mentiondchamber; and a conveyor extending through openings provided in the wallof the furnace and through said first-mentioned chamber and alongsidetheslot aforesaid, and adapted to move articles to be heated through thefurnace.

4. In a furnace of the class described, a-

heating chamber and means for heating the same; a second heating chamberin ermanently open communication with sai firstmentioned chamber througha slot extending alongside the same; means for heating said secondchamber to a temperature hi her than that of said first-mentioned chamer; a conveyor for articles to be heated extending through the furnaceand alongside the slot aforesaid; and an opening provided in the wall ofthe furnace and located opposite said slot.

5. In a furnace of the class described, a heating chamber and means forheating the same; a second heating chamber structurally independent ofsaid first-mentioned chamber and in permanently open communicationtherewith through an opening; means for heating said second chamber; anda conveyor for articles to be heated extending through saidfirst-mentioned chamber and adjacent the opening aforesaid.

6. In a furnace of the class described, a heating chamber and means forheating the same; a second heating chamber in permanently opencommunication with said firstmentioned chamber; means for heating saidsecond chamber to a temperature higher than that of said first-mentionedchamber; and means for moving articles to be heated through saidfirst-mentioned chamber, and portions only of the articles through thepermanently open communication aforesaid and into said second-mentionedchamber.

7. In a furnace of-the class described, a heating chamber and means forheating the same; a second heating chamber in permanently opencommunication with sald first mentioned chamber; means for heating saidsecond chamber to a temperature hi her than that of said first-mentionedcham er; means for moving articles to be heated through saidfirst-mentioned chamber, and portions only of the articles through thepermanently open communication aforesaid and into said second-mentionedchamber; and an opening provided in the Wall of the furnace adjacentsaid second-mentioned heating chamber and through which the heatedarticles may be removed from the furnace.

In testimony whereof I afiix my signature.

WILLIAM H. HAZARD.

